OH shoots I didn't know she was already getting advice from someone else. OOPS..Sorry Cyndi. I thought Sally was helping you.
Ducks take longer than chickens, and 40+ hours from initial pip is not uncommon for mine, but I've never hatched runners.
If the hole is open well enough for it to breathe, I'd leave it a bit longer.
If you can't see the bill, you could open the hole just a bit wider. If there is any exposed membrane, a little vaseline on it won't hurt.